v3.19.3
Note 7 - Stockholders' Deficit (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2010
Jun. 30, 2019
Preferred Stock, Dividends Per Share, Declared $ 0 $ 0      
Common Stock, Shares Authorized 5,313,200 148,000,000     95,000,000
Common Stock, Par or Stated Value Per Share $ 0.001 $ 0.001     $ 0.001
Common Stock, Shares, Outstanding, Ending Balance 701,808 19,548,969     5,807,877
Common Stock, Dividends, Per Share, Declared $ 0        
Conversion of Preferred Stock to Common Stock [Member]          
Equity, Convertible, Aggregate Proceeds Trigger $ 40        
Equity, Convertible, Stock Price Trigger $ 1.00        
Noncumulative Dividends for Holders of Series B Convertible Preferred Stock [Member]          
Dividends Payable, Amount Per Share 0.0251        
Noncumulative Dividends for Holders of Series A Convertible Preferred Stock [Member]          
Dividends Payable, Amount Per Share $ 0.0182        
Convert Notes and Accrued Interest to Series A Preferred Stock [Member]          
Debt Conversion, Converted Instrument, Shares Issued       3,531,889  
Convert Notes and Accrued Interest to Series B Preferred Stock [Member]          
Debt Conversion, Converted Instrument, Shares Issued     6,469,356    
Series A Redeemable Convertible Preferred Stock Without Giving Effect To The Reverse Stock Split [Member]          
Redeemable convertible preferred stock, shares issued (in shares) 2,034,548 56,672,658     0
Redeemable convertible preferred stock, shares outstanding (in shares) 2,034,548 56,672,658     0
Series B Redeemable Convertible Preferred Stock Without Giving Effect To The Reverse Stock Split [Member]          
Redeemable convertible preferred stock, shares issued (in shares) 1,833,387 51,069,262      
Temporary Equity, Remaining Shares Outstanding Requirements To Elect One Director 10,000,000        
Redeemable convertible preferred stock, shares outstanding (in shares) 1,833,387 51,069,262     0
Series B Convertible Preferred Stock [Member]          
Temporary Equity, Liquidation Preference Per Share $ 0.3133        
Series A Convertible Preferred Stock [Member]          
Temporary Equity, Liquidation Preference Per Share $ 0.2276